实验目的：验证delay参数的作用
standby 1 preempt delay minimum 150
-------------à防止优先级高的路由器（R3）重起后立即将状态变为active，而此时它（R3）并未完全学到路由，在抢夺过程中导致了不可达的情形

R1的配置 （为了实验效果明显将hello的间隔变得很大，使得OSPF收敛变慢）
interface Loopback0

ip address 1.1.1.1 255.255.255.0
!
interface Serial1/0

ip address 12.1.1.1 255.255.255.0

ip ospf hello-interval 50
!
interface Serial2/0

ip address 13.1.1.1 255.255.255.0

ip ospf hello-interval 50
!
router ospf 10

router-id 1.1.1.1

log-adjacency-changes

network 1.1.1.0 0.0.0.255 area 0

network 12.1.1.0 0.0.0.255 area 0

network 13.1.1.0 0.0.0.255 area 0

R2的配置
interface Loopback0

ip address 2.2.2.2 255.255.255.0
!
interface Ethernet0/0

ip address 10.1.1.2 255.255.255.0

standby 1 ip 10.1.1.1

standby 1 preempt
standby 1 priority 100

standby 1 track Serial2/0
!
interface Serial2/0

ip address 12.1.1.2 255.255.255.0

ip ospf hello-interval 50
!

router ospf 10

router-id 2.2.2.2

log-adjacency-changes

passive-interface Ethernet0/0

network 10.1.1.0 0.0.0.255 area 0

network 12.1.1.0 0.0.0.255 area 0


R3的配置：
interface Loopback0

ip address 3.3.3.3 255.255.255.0
!
interface Ethernet0/0

ip address 10.1.1.3 255.255.255.0

standby 1 ip 10.1.1.1

standby 1 priority 200

standby 1 preempt
standby 1 track Serial1/0
!
interface Serial1/0

ip address 13.1.1.3 255.255.255.0

ip ospf hello-interval 50

serial restart-delay 0
!
router ospf 10

router-id 3.3.3.3

log-adjacency-changes

passive-interface Ethernet0/0

network 10.1.1.0 0.0.0.255 area 0

network 13.1.1.0 0.0.0.255 area 0

R4的配置
！no ip routing
！
interface Ethernet0/0

ip address 10.1.1.4 255.255.255.0
!
！ip default-gateway 10.1.1.1

测试：
没有加delay参数时，ping1.1.1.1时，重起R3出现了很多U
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!!!
!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!
!U!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!!!
!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!
!!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!
!!U!!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!!!U!!!!!!!!!!!!!
!!!!!!!!!!!!!U!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
使用了standby 1 preempt delay minimum 150
ping1.1.1.1时，重起R3我们发现达到了完美的切换
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

参数起了很大的作用,直接决定快慢